Apparatus for tightening form wires



Aug. 12 1924. 1,504,647

2. W. SCOTT APPARATUS FOR TIGHTENING FORM WIRES Filed May 1 1923 IN VEN TOR.

A TTORNEYS Patented Aug. 12, 1924.

UNITED STATES PATENT QFic ZALOS W. SCOTT, OF SANTA BARBARA, CALIFORNIA.

APPARATUS FOR, TIGHTENING FORM WIRES.

Application filed May 16, 1923-. Serial No. eeas e.

To all whom it may concern.

Be it known that I, ZALOS l/V. Sooner, a citizen of the United States, residing at Santa Barbara, in the county of Santa-Bar- 5 bara and State of California, have invented.

members of forms employed in the con struction of concrete walls.

One of the main objects of the invention is to effect tightening of the form wires without weakening them. Ordinarily a form wire is strung through the sides of the form and connected to make an endless band, and a nail or the like is inserted between the opposite members of the band between the form members and is rotated to effect twisting of the wireband, said twisting resulting in shortening of the band so as to make it taut to hold the form members against spreading further apart. While the wire band is thus being twisted it gets tighter and tighter. Most of the twisting being effected while the band is relatively tight, causes crystallization of the metal of which the wire is made so that, even when the wire does not break at the time of tightening it, it is quite liable to be broken by theextra strain put upon it when the concrete is poured into place between the form members, the weight of said concrete tending to spread the form members further apart and thus exert a pull upon the form wires.

Another object of the invention is to provide for tightening of the form wires without any material crystallization of the metal of which said wires are constructed.

In order to avoid crystallizing the metal of which the form wires are constructed the form wires are twisted while slack and then drawn taut. i

The accompanying drawings illustrate the invention:

Figure 1 is a side elevation of an apparatus constructed in accordance with the, pro visions of the invention, the same being shown in operating position on one of a pair of form members and a form wire being shown connecting the form members and attached to the apparatus. Broken lines. indicate an abutment inserted between the yoke and rotating head.

Fig. 2 is a plan view of Figure 1, omittin the abutment.

Fig. 3 is an enlarged fraginental inverted plan section on the line indicated by 33, Figure 1.

Fig. 4; is an end view of the frame looking toward the right in Fig. 1.

Fig. 5 is a side elevation of a portion of the rotating head.

Fig. 6 is an elevation of Figure 4 from the right thereoff The form wire to be operated on is indicated at 11 and is shown in position to tie together a pair of form members, in-

dicated at 12, between which the concrete is poured to form a wall in a manner well understood in the art relating to the manufacture of reinforced concrete structures. The form wire 11, after being strung be,- tween the form. members, will be twisted together near its opposite ends by making one turn, as indicated at 13, to produce a band ofthe form wire. This operation may be performed by hand and the form wire will be more or less slack, as no effort is made to tighten the same by hand. As many form wires as desired may be thus loosely placed in position ready for the tightening operations.

To effect the tightenin of the form wire 11, the opposite ends 0 the wire will be looped over fingers 14 constituting the op osite ends of a rotating head, indicated 111 general by the character 15. Portions of the wire preferably engage in grooves 16 that lie between the finger 141 and other fingers 17 that are parallel to} the finger 14 and that are shorter than the finger lei, as clearly shown in Figure 6.- Preferably a half hitch is formed at each end of the wire, the end portions of the wire lying under other portions thereof and upon beveled end faces 18 of the head so that the greater the strain on the wire 11. the more firmly will the underlying portions of the wire be gripped. The wire may be secured to the head by any other suitable means within the scope of the invention. The head 15 is rotatably mounted. in this instance, on the unthreaded shank 19 of a screw 20 which is threaded through a nut, 2.1 that constitutes the intermediate portion of a frame 22, said frame, in this instance, being U-shaped or in the form of a yoke. The opposite ends of the yoke are bifurcated, as indicated at 221, so as to embrace the upright of one of the form braced by the bifurcated ends of the yoke.

Preferably the bifurcated ends are offset in opposite directions from the plane of the yoke body so that the yoke legs, when in position 'onthe form member, will'not lie centrally with respect to said form member but will be more or less eccentric thereto ends 221 of the yoke legs, herembefore refor a purpose hereinafter mentioned.

'The head 15 is held'in position by a washer 24 on the screw and a pin 25 extending transversely through the screw. The outer end of the screw 20 is provided with a suitable handle 26 whereby toforcibly rotate the screw. V The apparatus described above operates as follows:

Assuming that the form. wire has been placed in position, as above described, with its ends connected to the head 15, the operator will grasp the head 15 and rotate it in the direction tofurtherrtwist the wir 11 in the same direction. as the initial twist 13, all of the twisting occurring between the ends of the wire and the adjacent form member '12. l Vhile performing this twisting operation. the operator will feed the screw120 inwardly so as to effect twisting while maintaining the wire in a slack condition. This is quite important so as to prevent crystallization of the metal of which the wire is made, since crystallization would materially lessen the strength of the wire and make it liable to break under the strain produced when the concrete is poured into the form.

After the head 15 has been rotated to twist the. oppositeportions of the wire together for a sufficient number of turns to insure against parting of the wire band at the joint thus effected, the head 15 will be held against rotation by the operators hand or, preferably, a suitable abutment, indicated in broken lines at 27 in Figure 1, will be inserted between one leg of the yoke and the head 15 in a manner to prevent rotation ,of the head when the screw 20 is retracted or screwed outwardly. In this instance, the abutment 27 is merely the handle of a hammer. The screw 20 will then be retracted, thus increasing the distance between the head 15 and theadjacent form member 12,

thus pulling the wire 11 taut. In the tightening operation, the twisted portion 13 of the wire is pulled away from the adjacent form member so as to produce a space between the twisted portion and said form member, and this space will then be blocked by inserting a suitable element 28, preferably of triangular cross section with the tightening another form wire in the same manner as above described.

The offset construction of the bifurcated ferred to, greatly facilitates the inserting of the element 28 and wedge 29 as they can scribed, comprising a frame to engage a form member, a screw threaded through the frame and provided with an unthreaded shank, and ahead rotatably mounted on the shank and constructed for securing a form wire thereto.

2. An apparatus of the character described, comprising a frame to engage a form member, a screw threaded through the frame and provided with an unthreaded shank, a head rotatably mounted on the shank with its ends extending on opposite sides of the screw, and means at each end of the head to retain a half hitch of wire.

3. An apparatus of the character described, comprising a frame to engage a form member, a screw threaded through the frame and provided with an unthreaded shank, and a head rotatably mounted on the shank with its ends extending on opposite sides of the screw and having a pair of grooves in each end, the ends of the head having beveled faces adjacent to the grooves.

t. An apparatus of the character described, comprising a yoke having its opposite ends bifurcated, said ends being offset in opposite directions from the plane of the yoke body, a screw threaded through. the frame and provided with an unthreadcd shank, and a head rotatably mounted on the shank and provided with wire engaging means on opposite sides of the screw.

Signed at Santa Barbara, Calif, this 8th day of May, 1923.

' ZALOS W. SCOTT. 

